memory increase is worth far more than upgrading any other component.
Desktop with 8 GiB and 1 Mb/s spent 2+ weeks to download blockchain.
Virtual machine with 256 (or 512, not sure) MiB and 100 Mb/s spent 1.5 days for the same.
RAM is not the silver bullet.
RAMdisk, not only RAM. The biggest bottleneck is disk access, when disk == ram, that goes away.